Correlation Analysis of the Physicochemical Properties, Steaming Quality and Impedance Characteristics of Potato Tubers

The physicochemical properties, steaming quality, and impedance characteristics of different potato tuber varieties were tested and analyzed for correlations. The test aimed to provide a theoretical basis for developing a rapid detection technology to evaluate the cooking quality of potatoes based on electrical impedance spectroscopy (EIS). The results showed significant differences (P<0.05) in dry matter, starch, amylose, and dietary fiber content among the different potato varieties. Among them, variety 15049-11 had the highest dry matter, starch, and amylose content, with values of 23.11%, 80.46%, and 32.85%, respectively. The textural quality indicators of steamed potatoes (fracturability, hardness, adhesiveness, and gumminess) were significantly positively correlated (P<0.05) with their basic components (dry matter, starch, amylose, soluble dietary fiber, insoluble dietary fiber, and total dietary fiber) as well as with the gelatinization temperature, retrogradation value, particle size, swelling power, and solubility of potato starch. Fresh potatoes of varieties 002-18 and 15049-11 exhibited a more ordered and regular cell arrangement. After steaming, they retained relatively intact cell wall contours, and the cells were filled with a gelatinized starch matrix, resulting in higher brittleness and hardness. EIS testing showed that the textural characteristics of the steamed potatoes were significantly and positively correlated (P<0.05) with their impedance values in the low-frequency range (10~100 Hz). Therefore, EIS is expected to be an effective technology for the rapid characterization of the textural quality of steamed potatoes.